Monday, March 14, 2016

Holography and Quantum Error Correcting Codes: TGD View

Strong form of holography is one of the basic tenets of TGD, and I have been working with topological quantum computation in TGD framework with the braiding of magnetic flux tubes defining the space-time correlates for topological quantum computer programs. Flux tubes are accompanied by fermionic strings, which can become braided too and would actually represent the braiding at fundamental level. Also time like braiding of fermionic lines at light-like 3-surfaces and the braiding of light-like 3-surfaces themselvs is involved and one can talk about space-like and time-like braidings. These two are not independent being related by dance metaphor (think dancers at the parquette connected by threads to a wall generating both time like and space-like braidings). I have proposed that DNA and the lipids at cell membrane are connected by braided flux tubes such that the flow of lipids in lipid layer forming liquid crystal would induce braiding storing neural events to memory realized as braiding.

I have a rather limited understanding about error correcting codes. Therefore I was happy to learn that there is a conference in Stanford in which leading gurus of quantum gravity and quantum information sciences are talking about these topics. The first lecture that I listened was about a possible connection between holography and quantum error correcting codes. The lecturer was Preskill and the title of the talk was "Holographic quantum error-correcting codes: Toy models for the bulk/boundary correspondence" (see this and this). A detailed representation can be found in the article of Preskill et al ).

The idea is that time= constant section of AdS, which is hyperbolic space allowing tessellations, can define tensor networks. So called perfect tensors are building bricks of the tensor networks providing representation for holography. There are three observations that put bells ringing and actually motivated this article.

Perfect tensors define entanglement which TGD framework corresponds negentropic entanglement playing key role in TGD inspired theory of consciousness and of living matter.

In TGD framework the hyperbolic tesselations are realized at hyperbolic spaces H3(a) defining light-cone proper time hyperboloids of M4 light-cone.

TGD replaces AdS/CFT correspondence with strong form of holography.

Could one replace AdS/CFT correspondence with TGD version of holography?

One can criticize AdS/CFT based holography because it has Minkowski space only as a rather non-unique conformal boundary resulting from conformal compactification. Situation gets worse as one starts to modify AdS by populating it with blackholes. And even this is not enough: one can imagine anything inside blackhole interiors: wormholes connecting them to other blackholes, anything. Entire mythology of mystic creatures filling the white (or actually black) areas of the map. Post-modernistic sloppiness is the problem of recent day theoretical physics - everything goes - and this leads to inflationary story telling. Minimalism would be badly needed.

AdS/CFT is very probably mathematically correct. The question is whether the underlying conformal symmetry - certainly already huge - is large enough and whether its proper extension could allow to get rid of admittedly artificial features of AdS/CFT.

In TGD framework conformal symmetries are generalized thanks due to the metric 2-dimensionality of light-cone boundary and of light-like 3-surfaces in general. The resulting generalization of Kac-Moody group as super-symplectic group replaces finite-dimensional Lie group with infinite-dimensional group of symplectic transformations and leads to what I call strong form of holography in which AdS is replaced with 4-D space-time surface and Minkowski space with 2-D partonic 2-surfaces and their light-like orbits defining the boundary between Euclidian and Minkowskian space-time regions: this is very much like ordinary holography. Also imbedding space M4× CP2 fixed uniquely by twistorial considerations plays an important role in the holography.

AdS/CFT realization of holography is therefore not absolutely essential. Even better, its generalization to TGD involves no fictitious boundaries and is free of problems posed by closed time-like geodesics.

Preskill et al suggest a representation of holography in terms of tensor networks associated with the tesselations of hyperbolic space and utilizing perfect tensors defining what I call negentropic entanglement. Also Minkowski space light-cone has hyperbolic space as proper time=constant section (light-cone proper time constant section in TGD) so that the model for the tensor network realization of holography cannot be distinguished from TGD variant, which does not need AdS at all.

The interpretational problem is that one obtains also states in which interior local states are non-trivial and are mapped by holography to boundary states are: holography in the standard sense should exclude these states. In TGD this problem disappears since the macroscopic surface is replaced with what I call wormhole throat (something different as GRT wormhole throat for which magnetic flux tube is TGD counterpart) can be also microscopic.

Physics of living matter as physics condensed dark matter at magnetic bodies?

A very attractive idea is that in living matter magnetic flux tube networks defining quantum computational networks provide realization of tensor networks realizing also holographic error correction mechanism: negentropic entanglement - perfect tensors - would be the key element! As I have proposed, these flux tube networks would define kind of central nervous system make it possible for living matter to experience consciously its biological body using magnetic body.

These networks would also give rise to the counterpart of condensed matter physics of dark matter at the level of magnetic body: the replacement of lattices based on subgroups of translation group with infinite number of tesselations means that this analog of condensed matter physics describes quantum complexity.

I am just a novice in the field of quantum error correction (and probably remain such) but from experience I know that the best manner to learn something new is to tell the story with your own words. Of course, I am not at all sure whether this story helps anyone to grasp the new ideas. In any case, if one have a new vision about physical world, the situation becomes considerably easier since creative elements enter to the story re-telling. How these new ideas could be realized in the Universe of TGD bringing in new features relating to the new views about space-time, quantum theory, and living matter and consciousness in relation to quantum physics.

I was just thinking, what does TGD suggest about strong holography in relation to theory of consciousness, and came to check the blog, and found this. Thank You! :)

"Error correcting" reminds of experiences of shamanistic (auto)healing. I like the ideas of narratology, re-telling stories of and into dynamically holographic part-whole relations, they feel good in these bodies. "Worm holes" associate beautifully with the 'Snake' of various mythological narratives referring to the geometric shapes seen during healing/error correcting states.

Philosophically, also math itself can be viewed as dynamic holographic narratology (instead of Platonic ontology), and renarrated from foundation of number theory. Holography means that 'part' is the 'whole', just in more limited resolution and complexity.

What does this mean for general theory of measuring? How to decide, e.g., what is "part" and what is "whole" in each situation? Ouroboros?

Why bother to build 4-D Universe is information is stored by 2-D structures one might ask. Maybe the redundancy making the information storage safe is the reason. It could also relate to the need of local and holistic representations.

Holography gives also quantum classical correspondence. One must express outcome of quantum measurement result classically. One does not measure directly four-momenta and spins directly but things which are classical: we experience the world in terms of classical conceps.

A further nice reason for holography is imagination. The space-time surfaces are more or less unqiuely determined by string world sheets and partonic 2-surfaces - 2-D data. This has counterpart also in fermionic sector - error corrrectig codes. In p-adic sector pseudo-constants make the correspondence highly non-unique. Imagination! Most imaginations are not realisable!

About Me

I am a Finnish theoretical physicist. For last 37 years Topological Geometrodynamics has been both the passion and mission of my life. TGD is a noble attempt to construct a theory of everything, not forgetting consciousness. I have four children, who have brought a lot of happiness to my life. I live in Hanko, a small seaside town in southern Finland. I love almost all kinds of music but if I had to give just one name I would have difficulties in deciding between Chopin and Beethoven.

The 37 years with TGD have produced an enormous amount of material covering basic
TGD as a mathematical theory, the applications of TGD ranging from Planck length scale
to cosmology, and TGD inspired theory of consciousness and of living matter as a macroscopic
quantum system. I have organized this material at my homepage as online books and articles.